Apparatus for processing samples

ABSTRACT

Disclosed is apparatus for treating samples, and a method of using the apparatus. The apparatus includes processing apparatus (a) for treating the samples (e.g., plasma etching apparatus), (b) for removing residual corrosive compounds formed by the sample treatment, (c) for wet-processing of the samples and (d) for dry-processing the samples. A plurality of wet-processing treatments of a sample can be performed. The wet-processing apparatus can include a plurality of wet-processing stations. The samples can either be passed in series through the plurality of wet-processing stations, or can be passed in parallel through the wet-processing stations.

[0001] This application is a Continuation application of applicationSer. No. 09/504,083, filed Feb. 15, 2000, which is a Continuationapplication of Ser. No. 08/470,442, filed Jun. 6, 1995, which is aDivisional application of Ser. No. 07/987,171, filed Dec. 8, 1992, whichis a Continuation-in-part application of application Ser. No.07/638,378, filed Jan. 7, 1991, the contents of which are incorporatedherein by reference in their entirety, which is a Divisional applicationof application Ser. No. 477,474, filed Feb. 9, 1990.

BACKGROUND OF THE INVENTION

[0002] This invention relates to a method of processing a sampleincluding an etching step, and to an apparatus for carrying out such amethod, and more particularly to a processing method and apparatus whichis suitable for processing a sample in the manufacture of asemiconductor device or other device including miniaturized components

[0003] A sample such as a semiconductor device substrate is etched by achemical solution or by plasma, for example. Sufficient care must bepaid to corrosion protection of the sample after etching processing.

[0004] A corrosion-proofing technique after etching is disclosed, forexample, in U.S. Pat. No. 4,487,678. This technique subjects a resistfilm, after etching by plasma inside an etching chamber, to removal in asecond plasma processing chamber connected to the etching chamber. Thesecond plasma treatment removes chlorine compounds which are corrosivecomponents remaining in the resist film or on the etched surface. It isalso known to heat the sample after etching to at least 200° C. in orderto promote evaporation of chlorides that are residual corrosivecomponents. Japanese Laid-Open Patent Publication No. JP-A-61-133388discloses a method in which a sample after plasma etching is transferredto a heat-treating chamber in which hot air is blown on it to removecorrosive compounds. Thereafter the sample is washed with water anddried.

[0005] The present applicants have found that these aforementionedtechniques involve the problem that sufficient corrosion-proofingperformance cannot be obtained, at least for certain kinds of samples.

[0006] For instance, the techniques described above are believedeffective in some cases for corrosion-proofing of a single metallic filmsuch as an aluminum (Al) wiring film. However, they fail to provide asufficient corrosion-proofing effect after etching of a sample havingmetals having mutually different ionization tendencies such as films ofAl, Cu, W, Ti, Mo, etc. and their alloys or laminates, e.g., as alaminate wiring structure.

[0007] With the remarkable progress in miniaturization in recent years,wiring films have been more and more miniaturized, and an Al—Cu—Si alloyfilm having a few percent of Cu content in place of the conventionalAl—Si alloy film and a laminate structure of the Al—Cu—Si alloy film anda refractory metal film such as titanium tungsten (TiW), titaniumnitride (TiN) and molybdenum silicon (MoSi) film for reducing contactresistance have gained wide application as a wiring film in order toprevent breakage due to electromigration and stress migration. In such awiring film structure, ionization tendencies of Al and Cu, W, Ti, Mo orthe like are different so that a battery action develops due to wateracting as an electrolyte, and corrosion of the wiring film isaccelerated by so-called “electrolytic corrosion”. Even if corrosivematerials generated by etching are removed by utilizing plasma at a hightemperature of 200°0 C. or above, corrosion occurs due to the effect ofmoisture on remaining corrosive compounds within some minutes or severalhours after the sample is withdrawn into the atmosphere.

[0008] As a countermeasure of the above “electrolytic corrosion”problem, there has been proposed, as disclosed in Japanese Laid-OpenPublication No. Hei 2-2242233, a sample processing apparatus comprisingmeans for processing a sample (e.g., etching processing the sample),means for post-processing a processed sample, the post-processing meansutilizing a plasma, means for wet-processing a processed sampleprocessed through the plasma post-processing means, and means fordry-processing a processed sample which has been processed through thewet-processing means. Corrosion of the sample after the etchingprocessing, irrespective of the kind of the sample, can be preventedeffectively utilizing this sample processing apparatus.

[0009] However, since the sample processing apparatus shown in theabove-discussed Japanese Laid-Open Publication No. Hei 2-2242233comprises a single means for wet-processing the sample processed throughthe plasma post-processing means, the through-put is limited; moreover,when the wet-processing time is lengthened, such that thecorrosion-preventing effect is improved, a further problem is causedthat the through-put is even further lowered.

SUMMARY-OF THE INVENTION

[0010] It is an object of the present invention to provide a sampleprocessing method and apparatus which can prevent sufficiently corrosionof a sample after etching irrespective of the kind of sample.

[0011] Another object of the present invention is to provide a sampleprocessing method and apparatus wherein through-put of the processingcan be increased without a loss in the corrosion-preventing effect.

[0012] The above and other objects of the present invention and novelfeatures will be clear from the description of the present specificationand also from the attached drawings. This description and drawings arenot limiting of the invention, the scope of the present invention beingdefined by the claims.

[0013] Within the invention disclosed in the present application, anoutline of a representative example will be explained in the following.This representative example illustrates, and is not limiting of, thepresent invention.

[0014] According to one aspect of the present invention, a sampleprocessing apparatus comprises means for processing a sample (e.g., anetching processing means, such as a plasma etching means), means forplasma post-processing a sample, that has been processed through theprocessing means, under a reduced pressure condition, means forwet-processing a sample that has been processed through the plasmapost-processing means and means for dry-processing a sample that hasbeen processed through the wet-processing means. This aspect of thepresent invention includes techniques for using this apparatus.

[0015] According to a further aspect of the present invention, a sampleprocessing apparatus can include means for processing a sample (e.g., anetching processing means, such as a plasma etching means); a plurality(e.g., two) of wet-processing means, for processing samples passedthrough the sample processing means; and, e.g., means for dry-processinga sample that has been passed through the wet processing means. Thisaspect of the present invention also includes methods of using thisapparatus.

[0016] The plurality of wet processing means can be used in series, orcan be used in parallel (that is, samples can alternatively be passed toone or another of the wet-processing means, e.g., to an unoccupiedwet-processing means) to decrease processing time. In such use ofwet-processing means in parallel, there is overlapping use of thewet-processing means. Through parallel use of the wet-processing means,at least two of the wet-processing means are used simultaneously ondifferent samples, thereby decreasing total processing time for aplurality of samples, particularly where the wet-processing takes alonger time to perform than, e.g., the sample processing in the sampleprocessing means.

[0017] As a further aspect of the present invention, the wet-processingcan include a plurality of treatments (e.g., a chemical treatment in,e.g., an alkaline or acidic solution, together with a water rinse of asample).

[0018] In parallel passing of the samples through the wet processingmeans, a plurality of wet processing treatments can be performed at asingle wet processing means (station). In series passing of samplesthrough the plurality of wet-processing means (stations), a singlewet-processing treatment can be performed at each means; however, aplurality of wet-processing treatments can also be provided at eachmeans.

[0019] According to the present invention, the samples can also besubjected to additional treatment (means) for removing residualcorrosive compounds, formed, e.g., as a result of the sample processing(e.g., plasma etching), this additional treatment being performedbetween the sample processing and wet processing. This additionaltreatment can be a plasma processing, e.g., under a reduced pressure.

[0020] Passing of samples through the various processing stations can becontrolled by a controller (e.g., a personal computer), as would beknown by the ordinary worker in the art. This controller can be used toprovide series or parallel passing of samples through the wet-processingmeans.

[0021] According to the present invention, within a series of processingsteps comprising a step for processing a sample, a step for plasmapost-processing a processed sample under a reduced pressure condition, astep for wet-processing a processed sample of the plasma post-processingmeans and a step for dry-processing a processed sample of thewet-processing means, in the wet-processing step (which could causelowering of the through-put in the processing) plural wet-processingmeans are provided so that the lowering of the through-put in theprocessing does not occur; and, irrespective of the kind of the sample,it is possible to prevent effectively corrosion of the sample after theetching process.

[0022] In this description, a plasma treatment step, after sampleprocessing (e.g., plasma etching), is called post-processing, the liquidtreatment step is called wet-processing, and the drying step is calleddry-processing, for convenience.

[0023] In the invention, a sample is etched by use of plasma. Afteretching, the sample is post-processed by plasma post-processing means byutilizing plasma under a reduced pressure. The post-processed samplefrom the plasma post-processing means is wet-processed by wet-processingmeans. The wet-processed sample is dry-processed by dry-processingmeans. Since post-processing using plasma and wet-processing are bothcarried out, the corrosive materials that occur due to etching can beremoved sufficiently from the etched sample. Therefore, even when theetched sample is withdrawn into external air, for example, its corrosioncan be sufficiently prevented irrespective of the kind of sample.Moreover, treatment time can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the present invention will be described below byway of non-limitative example with reference to the accompanyingdrawings, in which:

[0025]FIG. 1 is a block diagram of a first sample processing apparatus;

[0026]FIG. 2 is a diagrammatic plan view of the apparatus of FIG. 1;

[0027]FIG. 3 is a diagrammatic longitudinal side view of the apparatusshown in FIG. 2;

[0028] FIGS. 4A-4G illustrate details of structure and operation of onepart of the apparatus of FIGS. 2 and 3;

[0029]FIGS. 5A and 5B illustrate details of structure and operation of asecond part of the apparatus of FIGS. 2 and 3;

[0030]FIG. 6 is a sectional view showing an example of a sample;

[0031]FIG. 7 is a perspective view showing an example of occurrence ofcorrosion;

[0032]FIG. 8 is a diagram showing the relation between processing modesafter etching and the time till occurrence of corrosion;

[0033]FIG. 9 is a block diagram of a second sample processing apparatus;

[0034]FIGS. 10 and 11 show, respectively, a diagrammatic plan view ofapparatus having a plurality of wet-processing means, and a diagrammaticlongitudinal side view of the apparatus shown in FIG. 10;

[0035]FIG. 12 shows a relationship between corrosion occurrence andacetic acid concentration when the wet processing includes an aceticacid treatment;

[0036]FIG. 13 shows a relationship between processing time and residualchlorine content on the surface of the sample;

[0037]FIG. 14 shows the buffering action of a weak acid-weak alkalibuffer liquid; and

[0038]FIG. 15 schematically shows a processing sequence for parallelprocessing of samples, over a period of time, in a plurality of wetprocessing means (stations).

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] In the following, the present invention will be described inconnection with preferred embodiments. The present invention is notlimited to these preferred embodiments (which are illustrative of theinvention), it being intended that the present invention is defined bythe full scope of the appended claims and equivalents thereof.

[0040] In FIG. 1, the sample processing apparatus includes a processingapparatus 10 for etching a sample, a plasma post-processing apparatus20, a wet-processing apparatus 30 and a dry-processing apparatus 40 andis equipped at least with means 50, 60, 70 for transferring the samplebetween these processing apparatuses.

[0041] In FIG. 1, an apparatus for processing, such as etching, thesample by utilizing plasma under a reduced pressure is used as theprocessing apparatus 10. Examples of the plasma etching apparatuseswhich may be employed are a plasma etching apparatus, a reactive sputteretching apparatus, a non-magnetic field type microwave plasma etchingapparatus, a magnetic field type microwave plasma etching apparatus, anelectron cyclotron resonance (ECR) type microwave plasma etchingapparatus, a photo-excitation plasma etching apparatus, a neutralparticle etching apparatus, and the like. Besides the apparatusesdescribed above, it is possible to employ an apparatus which wet-etchesthe sample and an apparatus which etches the sample by use of acorrosive gas.

[0042] In FIG. 1, the plasma post-processing apparatus 20post-processes, such as ashes (i.e. removes photoresist by oxidation),the processed sample processed by the processing apparatus 10 byutilizing plasma under a reduced pressure. Examples of theash-processing apparatuses which may be employed are a plasma ashingapparatus, non-magnetic field type and magnetic field type microwaveplasma ashing apparatuses, an ECR type microwave plasma ashingapparatus, a photo-excitation plasma ashing apparatus, and the like.

[0043] In FIG. 1, the wet-processing apparatus 30, such as spinning wetprocessing apparatus, wet-processes the post-processed sample from theplasma post-processing apparatus 20. In the spinning wet-processingapparatus, the post-processed sample is subjected to spinning washingwith water, for example, or to spinning washing sequentially withchemical solutions and water. In this case, the chemical solution isselected suitably in accordance with the materials to be removed fromthe post-processed sample. An inert gas atmosphere such as nitrogen gasor an atmospheric atmosphere is used as the processing atmosphere.Dry-processing such as water removal is sometimes conducted under thisstate after wet-processing. According to one aspect of the presentinvention, a plurality (at least two, e.g., two) of wet-processingstations are represented by wet-processing.

[0044] In FIG. 1, an apparatus for dry-processing the wet-processedsample from the wet-processing apparatus 30, such as an apparatus forheating and drying the wet-processed sample or an apparatus for blowinga dry gas on the wet-processed sample to dry it, is used as thedry-processing apparatus 40. A nitrogen gas atmosphere or atmosphericatmosphere is used as the processing atmosphere.

[0045] In FIG. 1, the sample transfer means 50 has the function oftransferring the processed sample between a processing station (notshown) of the processing apparatus 10 and a processing station (notshown) of the plasma post-processing apparatus 20. The sample transfermeans 60 has the function of transferring the post-processed samplebetween a processing station (not shown) of the plasma post-processingapparatus 20 and a processing station (not shown) of the wet-processingapparatus 30. The sample transfer means 70 has the function oftransferring the wet-processed sample between a processing station ofthe wet-processing apparatus 30 and a processing station (not shown) ofthe dry-processing apparatus 40. The sample transfer means 50 candeliver and receive the sample between the processing station of theprocessing apparatus 10 and that of the plasma post-processing apparatus20. The sample transfer means 60 can deliver and receive the samplebetween the processing station of the plasma post-processing apparatus20 and that of the wet-processing apparatus 30. The sample transfermeans 70 can deliver and receive the sample between the processingstation of the wet-processing apparatus 30 and that of thedry-processing apparatus 40. Known transfer means are used as the sampletransfer means 50, 60, 70. Examples of such means include an armconveyor equipped with sample scooping members that pick up and hold thesample which are rotated or reciprocated mechanically, electrically ormagnetically, or with sample grippers or sample adsorbers that grip andhold the sample at their outer peripheral edge by electromagneticadsorption or vacuum adsorption, for example, a belt conveyor having anendless belt spread between a driving roller and a driven roller, anapparatus for transferring the sample by blow force of gas, and thelike. If the processing apparatus 10 is the apparatus which processesthe sample by utilizing plasma under a reduced pressure, the sampletransfer means 50 is disposed in such a manner that the processed samplecan be transferred inside a reduced pressure space without being exposedto the external air.

[0046] In this case, there are shown disposed in FIG. 1 the sampletransfer means 80, which transfers the sample to be processed by theprocessing apparatus 10 thereto, and the sample transfer means 90, fortransferring the sample dry-processed by the dry-processing apparatus 40to a recovery cassette (not shown), for example. Sample transfer meansanalogous to the sample transfer means 50, 60 are used as these sampletransfer means 80 and 90.

[0047] If the processing apparatus 10 in FIG. 1 processes the sample byutilizing plasma under a reduced pressure, for example, the sampleprocessing atmosphere of the processing apparatus 10 can be put incommunication with, and cut off from, the space in which the sample tobe processed by the processing apparatus 10 is transferred thereto andthe space in which the processed sample is transferred. The sampleprocessing atmosphere of the plasma post-processing apparatus 20, thespace in which the processed sample is transferred and the space inwhich the post-processed sample is transferred can be put incommunication with, and cut off from, one another. The space in whichthe post-processed sample is transferred, the sample wet-processingatmosphere of the wet-processing apparatus 30, the space in which thewet-processed sample is transferred, the sample dry-processingatmosphere of the dry-processing apparatus 40 and the space to which thedry-processed sample is transferred may be maintained in communicationwith one another or may be put in communication with, and cut off from,one another.

[0048] In FIG. 1, the processing station is disposed in the sampleprocessing atmosphere of the processing apparatus 10. If the sampleprocessing apparatus 10 processes the sample by utilizing plasma under areduced pressure, the processing station is a sample table (not shown).The sample table (not shown) is disposed as the processing station ineach of the processing atmosphere of the plasma post-processingapparatus 20, the wet-processing apparatus 30 and the dry-processingapparatus 40. One or a plurality of samples can be put on each sampletable. In the processing apparatus 10 and in the plasma post-processingapparatus 20, each sample table is sometimes used as one of theconstituent elements forming the sample processing atmosphere.

[0049] An embodiment will be explained in further detail with referenceto FIGS. 2 and 3.

[0050] In FIGS. 2 and 3, an apparatus for processing the sample byutilizing plasma under a reduced pressure is used as the processingapparatus in this case.

[0051] In FIGS. 2 and 3, four openings 101 a, 101 b, 101 c and 101 d areformed in the top wall of a buffer chamber 100. An exhaust nozzle 102 ais disposed on the bottom wall of the buffer chamber 100. One of theends of an exhaust pipe (not shown) is connected to the exhaust nozzle102 a and its other end, to a suction port of an evacuation apparatus(not shown) such as a vacuum pump. The planar shape of the bufferchamber 100 is substantially L-shaped. The buffer chamber 100 is made ofa stainless steel in this case. When the buffer chamber 100 is viewed ona plan view, the openings 101 a, 101 b, 101 c are formed from the majorside to minor side of the L shape and the opening 101 d is formed on theminor side of the L shape. The openings 101 a-101 d have predeterminedgaps between the adjacent pairs of them. An arm 81 is disposed rotatablyinside the buffer chamber 100. The arm 81 can rotate in one plane in thebuffer chamber 100. A sample scooping member 82 is disposed at therotating end of the arm 81. The sample scooping member 82 has shapedelements opposed in a plane. The orbit of rotation substantially at thecenter of the sample scooping member 82 is positioned in such a manneras to substantially correspond to the center of each opening 101 a, 101b. In other words, the support point of rotation of the arm 81 ispositioned so that almost the center of the sample scooping member 82describes the orbit of rotation described above. The support point ofrotation of the arm 81 is positioned at the upper end of a rotary shaft83 whose upper end projects at that position into the buffer chamber100, whose lower end projects outside the buffer chamber 100 and whichis disposed rotatably on the bottom wall of the buffer chamber 100 whilekeeping air-tightness. The lower end of the rotary shaft 83 is connectedto rotation driving means (not shown) which is disposed outside thebuffer chamber 100 in such a manner as to correspond to the bottom wallof the buffer chamber 100. An arm 51 is disposed rotatably inside thebuffer chamber 100 at a position different from that of the arm 81 andon the opposite side of the sample path. The arm 51 can rotate in thesame plane in the buffer chamber 100 as the arm 81. A sample scoopingmember 52 is disposed at the rotating end of the arm 51. The planarshape of the sample scooping member 52 is substantially the same as thatof the sample scooping member 82. The arm 51 is disposed in such amanner that the orbit of rotation at the center of the sample scoopingmember 52 corresponds substantially to the center of each opening 101 b,101 c, 101 d. In other words, the support point of rotation of the arm51 is positioned at such a position where almost the center of thesample scooping member 52 describes the orbit of rotation describedabove. The support point of rotation of the arm 51 is positioned at theupper end of a rotary shaft 53 which is disposed rotatably on the bottomwall of the buffer chamber 100 while keeping air-tightness inside thebuffer chamber 100 with its upper end projecting at that position intothe buffer chamber 100 and with its lower end projecting outside thebuffer chamber 100. The lower end of the rotary shaft 53 is connected toa driving shaft of a rotation driving means disposed outside the bufferchamber 100 so as to correspond to the bottom wall of the buffer chamber100, such as a driving shaft of a motor 54.

[0052] In FIG. 3, a sample table 110 and a cover member 111 are disposedin such a manner as to interpose the opening 101 a between them. Thesample table 110 has a sample disposition surface on its surface. Theplanar shape and size of the sample table 110 are such that they canclose the opening 101 a. The sample table 110 is disposed inside thebuffer chamber 100 in such a manner as to be capable of opening andclosing the opening 101 a, and, in this case, is capable of moving upand down.

[0053] An elevation shaft 112 has its axis at the center of the opening101 a with its upper end projecting into the buffer chamber 100 and withits lower end projecting outside the same and is disposed on the bottomwall of the buffer chamber 100 in such a manner that it can move up anddown while keeping air-tightness inside the buffer chamber 100. Thesample table 110 is disposed substantially horizontally at the upper endof the elevation shaft 112 with its sample disposition surface being theupper surface. The lower end of the elevation shaft 112 is connected toelevation driving means, such as a cylinder rod of a cylinder 113, whichis disposed outside the buffer chamber 100 in such a manner as tocorrespond to the bottom wall of the latter. A seal ring (not shown) isdisposed around the outer periphery of the upper surface of the sampletable 110 or the inner surface of the top wall of the buffer chamber 100opposed to the former, that is, on the inner surface of the top wall ofthe buffer chamber 100 around the opening 101 a.

[0054] A sample delivery member (not shown) is disposed on the sampletable 110. The sample delivery member is disposed in such a manner as tobe capable of moving up and down between a position lower than thesample disposition surface of the sample table 110 and a position whichprojects outward from the opening 101 a when the opening 101 a is closedby the sample table 110. The planar shape and size of the cover member111 are such that they can close the opening 101 a. The cover member 111is disposed outside the buffer chamber 100 in such a manner as to becapable of opening and closing the opening 101 a, and, in this case, iscapable of moving up and down. In the case, an elevation shaft 114 isdisposed outside the buffer chamber 100 in such a manner as to becapable of moving up and down with its axis being substantially inconformity with that of the elevation shaft 112. The cover member 111 isdisposed substantially horizontally at the lower end of the elevationshaft 114. The upper end of the elevation shaft 114 is connected toelevation driving means, such as a cylinder rod of a cylinder 115, whichis disposed above the cover member 111 outside the buffer chamber 100.

[0055] A seal ring (not shown) is disposed around the outer periphery ofthe lower surface of the cover member 111 or the outer surface of thetop wall of the buffer chamber 100 opposed to the former, or in otherwords, around the outer surface of the top wall of the buffer chamber100 around the opening 101 a. The sample table 110 and the cover member111 are thus doors of an entry airlock of the buffer chamber 100.

[0056] A discharge tube 11, whose shape is substantially semi-sphericalin this case, is shown disposed hermetically on the top wall of thebuffer chamber 100 in FIG. 3. The shape and size of the opening of thedischarge tube 11 are substantially the same as those of the opening 101b, and the opening of the discharge tube 11 is substantially inagreement with the opening 101 b. The discharge tube 11 is made of anelectric insulator such as quartz. A waveguide 12 a is disposed outsidethe discharge tube 11 to surround it. A magnetron 13 as microwaveoscillation means and the waveguide 12 a are connected by a waveguide 12b. The waveguides 12 a and 12 b are made of an electric conductor. Thewaveguide 12 b has an isolator 12 c and a power monitor 12 d. A solenoidcoil 14 as magnetic field generation means is disposed outside andaround the waveguide 12 b.

[0057] A sample table 15 is disposed movably up and down inside thespace defined inside the buffer chamber 100 and the discharge tube 11.The axis of an elevation shaft 16 is substantially in agreement with theaxis of the discharge tube 11 in this case. The elevation shaft 16 isdisposed on the bottom wall of the buffer chamber 100, movably up anddown, with its upper end projecting into the buffer chamber 100 and withits lower end projecting outside the buffer chamber 100 while keepingair-tightness inside the buffer chamber 100.

[0058] More details of this part of the apparatus are given in FIGS. 5Aand 5B, to which reference should be made also.

[0059] The sample table 15 has a sample disposition surface on itssurface. The planar shape and size of the sample table 15 are such thatthe sample table 15 can penetrate through the opening 101 b. The sampletable 15 is disposed substantially horizontally at the upper end of theelevation shaft 16 with its sample disposition surface being its uppersurface. The lower end of the elevation shaft 16 is connected toelevation driving means, such as a cylinder rod of a cylinder (notshown), which is disposed outside the buffer chamber 100 in such amanner as to correspond to the bottom wall of the same. In this case,the lower end portion of the elevation shaft 16 is connected to a biaspower source, for example, a radio frequency power source 18. The radiofrequency power source 18 is disposed outside the buffer chamber 100 andis grounded. In this case, the sample table 15 and the elevation shaft16 are in an electrically connected state but the buffer chamber 100 andthe elevation shaft 16 are electrically isolated.

[0060] A sample delivery member 15 a (FIG. 5A) is disposed on the sampletable 15. The sample delivery member 15 a is disposed at a positionbelow the sample disposition surface of the sample table 15 and in sucha manner as to be capable of moving up and down with respect to thesample scooping members 82, 52 when the sample disposition surface ofthe sample table 15 is moved down below the sample scooping member 82 ofthe arm 81 and the sample scooping member 52 of the arm 51.

[0061] The sample table 15 has means for control of temperature. A heatmedium flow path is defined inside the sample table 15, for example, anda cooling medium as a heat medium such as cooling water, liquid ammonia,liquid nitrogen, or the like, or a heating medium such as heating gas,is supplied to the flow path. Heat generation means such as a heater,for example, is disposed on the sample table 15.

[0062] Flanges 120 and 121 are disposed around the sample table 15 andthe elevation shaft 16 inside the buffer chamber 100. The inner diameterand shape of each flange 120, 121 are substantially in conformity withthose of the opening 101 b. The flange 120 is disposed air-tight on theinner surface of the bottom wall of the buffer chamber 100 with the axisof the elevation shaft 16 being substantially at its center. The flange121 is disposed in such a manner as to oppose the flange 120. Metallicbellows 122 as extension-contraction cut means are disposed in such amanner as to bridge these flanges 120 and 121.

[0063] An elevation shaft 122 a is disposed movably up and down with itsupper end projecting into the buffer chamber 100 and with its lower endprojecting outside the buffer chamber 100 while keeping air-tightnessinside the buffer chamber 100. The flange 121 is connected to the upperend of the elevation shaft. The lower end of the elevation shaft isconnected to elevation driving means such as a cylinder rod of acylinder (not shown) disposed outside the buffer chamber 100 in such amanner as to correspond to the bottom wall of the buffer chamber 100.

[0064] A seal ring is disposed on the upper surface of the flange 121 orthe inner surface of the top wall of the buffer chamber 100 opposing theformer, or in other words, on the inner surface of the top wall of thebuffer chamber 100 around the opening 101 b.

[0065] An exhaust nozzle 102 b is disposed on the bottom wall of thebuffer chamber 100 more inward than the flange 120. One of the ends ofan exhaust pipe (not shown) is connected to the exhaust nozzle 102 b,and its other end to the suction port of an evacuation apparatus (notshown) such as a vacuum pump. A switch valve (not shown) and a pressureregulating valve such as a variable resistance valve (not shown) aredisposed in the exhaust pipe. One of the ends of a gas introduction pipe(not shown) is connected to a processing gas source (not shown), and itsother end opens into the discharge tube 11, or the like. A switch valveand a gas flow rate regulator (not shown) are disposed in the gasintroduction pipe.

[0066] In FIG. 3, the plasma post-processing chamber 21 is hermeticallydisposed on the top wall of the buffer chamber 100. The shape and sizeof the opening of the plasma post-processing chamber 21 aresubstantially in agreement with those of the opening 101 c, and theopening of the plasma post-processing chamber 21 is substantially inagreement with the opening 101 c. A sample table 22 is disposed in, thespace defined by the interior of the buffer chamber 100 and that of theplasma post-processing chamber 21. A support shaft 23 in this case usesthe axis of the plasma post-processing chamber 21 as its axis. It isdisposed on the bottom wall of the buffer chamber 100 with its upper endprojecting into the buffer chamber 100 and with its lower end projectingoutside the buffer chamber 100 while keeping air-tightness inside thebuffer chamber 100.

[0067] The sample table 22 has a sample disposition surface on itssurface. The planar shape and size of the sample table 22 are smallerthan those of the opening 101c in this case. The sample table 22 isdisposed substantially horizontally at the upper end of the supportshaft 23 with its sample disposition surface being the upper surface.The sample disposition surface of the sample table 22 is positionedbelow the sample scooping member 52 of the arm 51.

[0068] A sample delivery member (not shown) is disposed on the sampletable 22. In other words, the sample delivery member is disposed movablyup and down between a position lower than the sample disposition surfaceof the sample table 22 and a position higher than the sample scoopingmember 52 of arm 51.

[0069] Flanges 125 and 126 are disposed outside the sample table 22 andthe support shaft 23 but inside the buffer chamber 100. The innerdiameter and shape of each flange 125, 126 are substantially inconformity with those at the opening 101 c. The flange 125 is disposedhermetically on the inner surface of the bottom wall of the bufferchamber 100 substantially coaxial with the axis of the support shaft 23.The flange 126 opposes the flange 125. Metallic bellows 127 asextension-contraction cut means bridge between these flanges 125 and126. An elevation shaft (not shown) is disposed movably up and down onthe bottom wall of the buffer chamber 100 with its upper end projectinginto the buffer chamber 100 and with its lower end projecting outsidethe buffer chamber 100 while keeping air-tightness inside the bufferchamber 100.

[0070] The flange 126 is connected to the upper end of the elevationshaft. The lower end of the elevation shaft is connected to elevationdriving means such as a cylinder rod of a cylinder (not shown) which isdisposed outside the buffer chamber 100 so as to correspond to thebottom wall of the buffer chamber 100. A seal ring (not shown) isdisposed on the upper surface of the flange 126 or the inner surface ofthe top wall of the buffer chamber 100 opposing the upper surface of theflange 126, or, in other words, on the inner surface of the top wall ofthe buffer chamber 100 around the opening 101 c. An exhaust nozzle 102 cis disposed on the bottom wall of the buffer chamber 100 which is moreinward than the flange 125. One of the ends of an exhaust pipe (notshown) is connected to the exhaust nozzle 102 c, and its other end tothe suction port of an evacuation apparatus (not shown) such as a vacuumpump.

[0071] In FIG. 3, a sample table 130 and a cover member 131 are disposedin such a manner as to interpose the opening 101d between them. Thispart of the apparatus and its operation are shown in more detail inFIGS. 4A-G, to which reference should be made also. The sample table 130has a sample disposition surface on its surface. The planar shape andsize of the sample table 130 are such that the sample table 130 cansufficiently close the opening 101 d. The sample table 130 is disposedmovably up and down, in this case, inside the buffer chamber 100 in sucha manner as to be capable of opening and closing the opening 101 d. Inthis case, an elevation shaft 132 is disposed movably up and down on thebottom wall of the buffer chamber 100 with its upper end projecting intothe buffer chamber 100 and with its lower end projecting outside thebuffer chamber 100 while keeping air-tightness inside the buffer chamber100. The sample table 130 is disposed substantially horizontally at theupper end of the elevation shaft 132 with its sample disposition surfacebeing the upper surface. The lower end of the elevation shaft 132 isconnected to elevation driving means such as a cylinder rod of acylinder 133 which is disposed outside the buffer chamber 100 in such amanner as to correspond to the bottom wall of the buffer chamber 100.

[0072] A seal ring is disposed around the outer peripheral edge of theupper surface of the sample table 130 (as shown) or the inside of thetop wall of the buffer chamber 100 opposing the outer peripheral edge,that is, on the inner surface of the top wall of the buffer chamber 100around the opening 101 d. A sample delivery member 130 a is disposed onthe sample table 130. It is disposed movably up and down between aposition lower than the sample disposition surface of the sample table130 and a position projecting outward from the opening 101 d under thestate where the opening 101d is closed by the sample table 130.

[0073] The planar shape and size of a cover member 131 are such that thecover member 131 can open and close the opening 101 d. It is disposedmovably up and down, in this case, outside the buffer chamber 100. Theaxis of an elevation shaft 134 is substantially in agreement with thatof the elevation shaft 132, in this case. This elevation shaft 134 isdisposed movably up and down outside the buffer chamber 100. The covermember 131 is disposed substantially horizontally at the lower end ofthe elevation shaft 134. The upper end of the elevation shaft 134 isconnected to elevation driving means such as a cylinder rod of acylinder 135 which is disposed at a position above the cover member 131outside the buffer chamber 100. A seal ring is disposed around the outerperipheral edge of the lower surface of the cover member 131 (as shown)or the outer surface of the top wall of the buffer chamber 100 opposingthe former, that is, the outer surface of the top wall of the bufferchamber 100 around the opening 101 d. The sample table 130 and the covermember 131 thus constitute doors of an exit airlock for the bufferchamber 100.

[0074] A cassette table 140 is disposed movably up and down in such amanner as to correspond to the side surface of the L-shaped major sideof the buffer chamber 100 outside the buffer chamber 100. A guide 141 isdisposed outside the buffer chamber 100 in such a manner as to extendlinearly along the side surface of the L-shaped major side in itstransverse direction. The edge of this guide 141 on the side of thecassette table 140 is extended so as to correspond to the center of thecassette table 140, in this case. An arm 142 is a linear member in thiscase, and one of its ends is disposed on the guide 141 in such a manneras to be capable of reciprocation while being guided by the guide 141. Asample scooping number 143 is disposed at the other end of the arm 142.The cassette table 140 is disposed substantially horizontally at theupper end of an elevation shaft 144 with a cassette disposition surfacebeing its upper surface. The lower end of the elevation shaft 144 isconnected to elevation driving means 145.

[0075] The wet-processing chamber 31, the dry-processing chamber 41 anda sample recovery chamber 150 are disposed outside the buffer chamber100, in this case. They form a unit connectable to and disconnectablefrom the buffer chamber unit. The wet-processing chamber 31, thedry-processing chamber 41 and the sample recovery chamber 150 arealigned sequentially along the side walls on the side of the openings101 c, 101 d of the buffer chamber 100 in this case. Among them, thewet-processing chamber 31 is disposed at the position closest to theopening 101 d.

[0076] A sample table 32 is disposed inside the wet-processing chamber31. A support shaft 33 is disposed rotatably on the bottom wall of thewet-processing chamber 31 with its upper end projecting into thewet-processing chamber 31 and with its lower end projecting outside thewet-processing chamber 31 in such a manner as to keep air-tightness andwater-tightness inside the wet-processing chamber 31 in this case. Thelower end of the support shaft 33 is connected to a rotary shaft of amotor (not shown) as a rotation driving means, for example.

[0077] The sample table 32 has a sample disposition surface on itssurface. The sample table 32 is disposed substantially horizontally atthe upper end of the support shaft 33 with the sample dispositionsurface being its upper surface. The sample disposition surface of thesample table 32 is positioned below a sample scooping member 62 of anarm 61.

[0078] The sample table 32 is equipped with a sample delivery member(not shown). The sample delivery member is disposed movably up and downbetween a position below the sample disposition surface of the sampletable 32 and a position above the sample scooping member 62 of the arm61. A processing liquid feed pipe (not shown) is disposed inside thewet-processing chamber 31 in such a manner as to be capable of supplyinga processing solution to the sample disposition surface of the sampletable 32. A processing solution feed apparatus (not shown) is disposedoutside the wet-processing chamber 31. The processing solution feed pipeis connected to this processing solution feed apparatus. A waste liquordischarge pipe (not shown) is connected to the wet-processing chamber31. In this case, inert gas introduction means (not shown) forintroducing an inert gas such as nitrogen gas into the wet-processingchamber 31 are provided.

[0079] In FIGS. 2 and 3, the arm 61 is disposed rotatably so as tocorrespond to the sample tables 130 and 32. The arm 61 can rotate on thesame plane outside the buffer chamber 100. The sample scooping member 62is disposed at the rotating end of the arm 61. The planar shape of thesample scooping member 62 is substantially the same as those of thesample scooping members 52 and 82. The arm 61 is disposed in such amanner that the orbit of rotation of the center of the sample scoopingmember 62 corresponds substantially to the centers of the sample tables130 and 32, respectively. In other words, the support point of rotationof the arm 61 is positioned to a position where almost the center of thesample scooping member 62 describes the orbit of rotation describedabove.

[0080] The support point of rotation of the arm 61 is disposed at theupper end of the rotary shaft 63 disposed rotatably outside the bufferchamber 100 and outside the wet-processing chamber 31. The lower end ofthe rotary shaft 63 is connected to the driving shaft of a motor 64, forexample, as a rotation driving means. An opening 34 is bored on the sidewall of the wet-processing chamber 31 that corresponds to the rotationzones of the arm 61 and sample scooping member 62. The size and positionof the opening 34 are such that they do not prevent the entry and exitoperations of the arm 61 and sample scooping member 62 with respect tothe wet-processing chamber 31. The opening 34 can be opened and closedby switch means (not shown) in this case.

[0081] A sample table 42 is disposed inside the dry-processing chamber41. The sample table 42 has a sample disposition surface on its surface.It is disposed substantially horizontally on the bottom wall of thedry-processing chamber 41. A heater 43 is used as heating means in thiscase. The heater 43 is disposed on the back of the sample table 42 insuch a manner as to be capable of heating the sample table 42. It isconnected to a power source (not shown).

[0082] The sample disposition surface of the sample table 42 ispositioned below a sample scooping member 72 of an arm 71. A sampledelivery member (not shown) is disposed on the sample table 42. In otherwords, the sample delivery member is disposed movably up and downbetween a position below the sample disposition surface of the sampletable 42 and a position above the sample scooping member 72 of the arm71. In this case, the sample delivery member, too, is capable of movingup and down between a position below the sample disposition surface ofthe sample table 32 and a position above the sample scooping member 72of the arm 71. In this case, there is provided inert gas introductionmeans (not shown) for introducing an inert gas such as nitrogen gas intothe dry-processing chamber 41.

[0083] A cassette table 151 is disposed inside a sample recovery chamber150. An elevation shaft 152 is disposed movably up and down on thebottom wall of the sample recovery chamber 150 with its upper endprojecting into the sample recovery chamber and with its lower endprojecting outside the sample recovery chamber 150. The cassette table151 is disposed substantially horizontally at the upper end of theelevation shaft 152 with a cassette disposition surface being its uppersurface. The lower end of the elevation shaft 152 is disposed onelevation driving means 153. In this case, inert gas introduction means(not shown) are arranged so as to introduce an inert gas such asnitrogen gas into the sample recovery chamber 150.

[0084] In FIG. 2, a guide 73 is disposed along the inner wall surface ofeach of the wet-processing chamber 31, the dry-processing chamber 41 andthe sample recovery chamber 150. The guide 73 has a linear shape. Inother words, the line passing through the centers of the sample tables32, 42 and the cassette table 151 is a straight line and the guide 73 isdisposed substantially parallel to this line. The arm 71 is a linearmember in this case and one of its ends is disposed on the guide 73 soas to be capable of reciprocation while being guided by the guide 73. Asample scooping member 72 is disposed at the other end of the arm 71.

[0085] Openings (not shown) are formed on the side walls of the wet- anddry-processing chambers 31, 41 and the sample recovery chamber 150corresponding to the reciprocation zones of the arm 71 and the samplescooping member 72, respectively, so that the arm 71 and the samplescooping member 72 are not prevented from coming into and out from thewet-processing chamber 31, the dry-processing chamber 41 and the samplerecovery chamber 150, respectively. These openings can be opened andclosed by switch means (not shown), respectively. An opening for loadingand discharging a cassette and a door (not shown) are disposed in thesample recovery chamber 150.

[0086] A cassette 160 is disposed on a cassette table 140. It can storea plurality of samples 170 one by one stacked in the longitudinaldirection, and one of its side surfaces is open in order to take out thesamples 170 from the cassette 160. The cassette 160 is disposed on thecassette table 140 with its sample take-out side surface facing theopening 101 a. The cassette table 140 supporting the cassette 160thereon is moved down, for example, under this state. Descent of thecassette table 140 is stopped at the position where the sample 170stored at the uppermost stage of the cassette 160 can be scooped up bythe sample scooping member 143.

[0087] The operation of this apparatus is as follows:

[0088] The openings 101 a and 101 d are closed by the sample tables 110and 130, respectively, and when an evacuation apparatus is operatedunder this state, the inside of the buffer chamber 100 is evacuated to apredetermined pressure. Thereafter, the cover member 111 is moved up andthis ascent is stopped at the position where the sample scooping member143 for scooping up the sample 170 is not prevented from reaching theopening 101 a. The arm 142 is moved towards the cassette 160 under thisstate and this movement is stopped at the position where the samplescooping member 143 corresponds to the back of the sample 170 stored atthe lowermost stage of the cassette 160, for example. Thereafter thecassette 160 is moved up by the distance at which the sample scoopingmember 143 can scoop up the sample 170. In this manner the sample 170 isscooped up on its back by the sample scooping member 143 and deliveredto the sample scooping member 143.

[0089] When the sample scooping member 143 receives the sample 170, thearm 142 is moved towards the opening 101 a. This movement of the arm 142is stopped at the point where the sample scooping member 143 having thesample 170 reaches the position corresponding to the opening 101 a.Under this state the sample delivery member of the sample table 110 ismoved up so that the sample 170 is delivered from the sample scoopingmember 143 to the sample delivery member. Thereafter, the samplescooping member 143 is retreated to the position at which it does notprevent descent of the sample delivery member receiving the sample 170by the movement of the arm 142.

[0090] Thereafter the sample delivery member having the sample 170 ismoved down and the sample 170 is delivered from the sample deliverymember to the sample table 110 and placed on its sample dispositionsurface. Then, the cover member 111 is moved down. Accordingly, theopening 101 a is closed by the cover member 111 and its communicationwith the outside is cut off. Thereafter, the sample table 110 having thesample 170 is moved down and this downward movement is stopped at thepoint where the sample table 110 reaches the position at which thesample 170 can be exchanged between the sample delivery member of thesample table 110 and the sample scooping member 82 of the arm 81.

[0091] The flange 121 and the metallic bellows 122 are moved down by theshaft 122 a lest they prevent the rotation of the arm 81 and the samplescooping member 32 and the sample table 15 is moved down to the positionwhere its sample delivery member 15 a and the sample scooping member 82of the arm 81 can exchange the sample 170 between them. Under this statethe sample delivery member 15 a is moved up so that it can exchange thesample 170 with the sample scooping member 82 of the arm 81. The arm 81is then rotated in the direction of the sample table 110 and the samplescooping member 82 is located at the position which corresponds to theback of the sample 170 held by the sample delivery member of the sampletable 110 and at which it can scoop up the sample 170. Under this statethe sample delivery member of the sample table 110 is moved down and thesample 170 is delivered to the sample scooping member 82 of the arm 81.After scooping up the sample 170, the sample scooping member 82 isrotated in the direction of the sample table 15 while passing betweenthe flange 121 and the inner surface of the top wall of the bufferchamber 100 as the arm 81 is rotated in the direction of the sampletable 15.

[0092] The sample table 110 is moved up once again so that the opening101 a is closed by the sample table 110. The rotation of the samplescooping member 82 described above is stopped when the sample scoopingmember 82 reaches the position where the sample 170 can be exchangedbetween the sample scooping member 82 and the sample delivery member 15a of the sample table 15. The sample delivery member 15 a of the sampletable 15 is moved up under this state so that the sample 170 isdelivered from the sample scooping member 82 to the sample deliverymember 15 a of the sample table 15. Thereafter, when the arm 81 isrotated to the position between the openings 101 a and 101 b, the samplescooping member 82 is brought into the stand-by state to prepare for thenext delivery of the sample between the sample tables 110 and 15.

[0093] Thereafter the flange 121 and the metallic bellows 122 are movedup by the shaft 122 a so that communication of the buffer chamber 100 inthe metallic bellows 122 and the inside of the discharge tube 11 withthe interior of the buffer chamber 100 outside the metallic bellows 122is cut off. When the sample delivery member 15 a of the sample table 15receiving the sample 170 is moved down, the sample 170 is delivered fromthe sample delivery member 15 a of the sample table 15 to the sampletable 15 and is placed on the sample disposition surface of the sampletable 15. After receiving the sample 170 on its sample dispositionsurface, the sample table 15 is moved up to a predetermined position(see FIG. 5A) inside the space where communication with the bufferchamber 100 outside the metallic bellows 122 is cut off.

[0094] A predetermined processing gas is introduced at a predeterminedflow rate from the processing gas source into the space in whichcommunication with the buffer chamber 100 outside the metallic bellows122 is cut off. Part of the processing gas introduced into this space isexhausted outside the space due to the operations of the evacuationapparatus and the variable resistance valve. In this manner the pressureof this space is controlled to a predetermined pressure for etchingtreatment.

[0095] The magnetron 13 oscillates a 2.45 GHz microwave in this case.The microwave thus oscillated propagates through the waveguides 12 b and12 a through the isolator 12 c and the power monitor 12 d and isabsorbed by the discharge tube 11, thereby generating a radio frequencyfield containing the microwave. At the same time, the solenoid coil 14is operated to generate a magnetic field. The processing gas existinginside the space where communication with the buffer chamber 100 outsidethe metallic bellows 122 is cut off is converted to plasma due to thesynergistic operations of the radio frequency field containing themicrowave and the magnetic field. The sample 170 disposed on the sampletable 15 is etched by utilizing this plasma.

[0096] Thereafter the sample table 15 and the flange 121 are moveddownwardly (FIG. 5B) and the sample delivery member 15 a is movedupwardly.

[0097] The rotation of the sample scooping member 52 is stopped at thepoint when the sample scooping member 52 reaches the position where theetched sample 170 can be exchanged between the sample scooping member 52and the sample delivery member 15 a of the sample table 15. The sampledelivery member 15 a of the sample table 15 is moved down under thisstate and the etched sample 170 is delivered from the sample deliverymember 15 a of the sample table 15 to the sample scooping member 52 ofthe arm 51. After scooping up the etched sample 170, the sample scoopingmember 52 is rotated in the direction of the sample table 22 whilepassing between the flange 121 and the inner surface of the top wall ofthe buffer chamber 100 as the arm 51 is rotated in the direction of thesample table 22.

[0098] A new sample in the cassette 160 is placed by the operationsdescribed above on the sample table 15 from which the etched sample 170is removed. The new sample placed on the sample table 15 is subsequentlyetch-processed due to the operations described above.

[0099] Before, or during, the rotation of the sample scooping member 52having the etched sample 170, the flange 126 and the metallic bellows127 are moved down lest they prevent the rotation of the arm 51 and thesample scooping member 52. The radio frequency power source 18 isoperated at the time of etching of the sample 170, a predetermined radiofrequency power is applied to the sample table 15 through the elevationshaft 16 and a predetermined radio frequency bias is applied to thesample 170. The sample 170 is adjusted to a predetermined temperaturethrough the sample table 15.

[0100] The operations of the magnetron 13, solenoid coil 14 and radiofrequency power source 18, and the like, are stopped at the point whereetching of the sample 170 is complete, and introduction of theprocessing gas into the space whose communication with the inside of thebuffer chamber 100 outside the metallic bellows 122 is cut off isstopped. After evacuation of this space is conducted sufficiently, theswitch valve constituting the evacuation means is closed. Thereafter,the flange 121 and the metallic bellows 122 are moved down so as not toprevent the rotation of the arm 51 and the sample scooping member 52 andthe sample table 15 is moved down to the position where its sampledelivery member and the sample scooping member 52 of the arm 51 canexchange the etched sample 170. The sample delivery member of the sampletable 15 is then moved up so that it can exchange the etched sample 170with the sample scooping member 52 of the arm 51. When the arm 51 isrotated under this state in the direction of the sample table 15, thesample scooping member 52 passes between the flange 121 and the innersurface of the top wall of the buffer chamber 100 and is rotated in thedirection of the sample table 15.

[0101] The sample scooping member 52 having the etched sample 170 isrotated in the direction of the sample table 22 while passing betweenthe flange 126 and the inner surface of the top wall of the bufferchamber 100 when the arm 51 is rotated further in the direction of thesample table 22. Such a rotation of the sample scooping member 52 isstopped when the sample scooping member 52 reaches the position wherethe etched sample 170 can be exchanged between the sample scoopingmember 52 and the sample delivery member of the sample table 22. Thesample delivery member of the sample table 22 is moved up under thisstate and the etched sample 170 is delivered from the sample scoopingmember 52 to the sample delivery member of the sample table 22.Thereafter the sample scooping member 52 is rotated to the positionbetween the openings 101 c and 101 d and is brought into the stand-bystate.

[0102] Thereafter, the flange 126 and the metallic bellows 127 are movedup and the interior of the buffer chamber 100 inside the metallicbellows 127 and the interior of the plasma post-processing chamber 21are cut off from communication with the interior of the buffer chamber100 outside the metallic bellows 127. When the sample delivery member ofthe sample table 22 receiving the etched sample 170 is moved down, theetched sample 170 is delivered from the sample delivery member of thesample table 22 to the sample table 22 and is placed on the sampledisposition surface of the sample table 22.

[0103] The post-processing gas is introduced at a predetermined flowrate into the space whose communication with the interior of the bufferchamber 100 outside the metallic bellows 127 is cut off, and part of thepost-processing gas is exhausted from this space. In this manner thepressure of this space is adjusted to a predetermined post-processingpressure. Thereafter, the post-processing gas existing in this space isconverted in this case to plasma due to the operation of a radiofrequency field containing a microwave. The etched sample 170 placed onthe sample table 22 is post-processed by utilizing this plasma.

[0104] After the post-processing of the etched sample is thus complete,introduction of the post-processing gas into the space, which is cut offfrom the interior of the buffer chamber 100 outside the metallic bellows127, and conversion to plasma of the post-processing gas are stopped.Then, the flange 126 and the metallic bellows 127 are moved down lestthey prevent the rotation of the arm 51 and the sample scooping member52.

[0105] The sample scooping member 52 that is under the stand-by statebetween the openings 101 c and 101 d is rotated to the position whichdoes not prevent the rise of the post-processed sample 170 on the sampletable 22 and which has passed the sample table 22. The sample deliverymember of the sample table 22 is moved up under this state so that thepost-processed sample 170 placed on the sample table 22 is delivered tothe sample delivery member of the sample table 22. Then, when the arm 51is rotated in the direction of the sample table 22, the sample scoopingmember 52 is located to the position at which it can scoop up the sample170, so as to correspond to the back of the post-processed sample 170held by the sample delivery member of the sample table 22. The sampledelivery member of the sample table 22 is moved down under this stateand the post-processed sample 170 is delivered from the sample deliverymember of the sample table 22 to the sample scooping member 52 of thearm 51.

[0106] After receiving the post-processed sample 170, the samplescooping member 52 is rotated in the direction of the sample table 130while passing between the flange 126 and the inner surface of the topwall of the buffer chamber 100 when the arm 51 is rotated in thedirection of the sample table 130. After the post-processed sample 170is removed, the next etched sample is placed on the sample table 22 andis then post-processed by utilizing plasma.

[0107] Before, or during, the rotation of the sample scooping member 52having the post-processed sample 170 as described above, the sampletable 130 is moved down to the position at which its sample deliverymember 130 a and the sample scooping member 52 of the arm 51 canexchange the post-processed sample 170. The rotation of the samplescooping member 52 is stopped when it reaches the position at which thepost-processed sample 170 can be exchanged between the sample scoopingmember 52 and the sample delivery member 130 a of the sample table 130(FIG. 4A). The sample delivery member 130 a of the sample table 130 ismoved up under this state so that the post-processed sample 170 isdelivered from the sample scooping member 52 to the sample deliverymember 130 a of the sample table 130 (FIG. 4B).

[0108] Thereafter, when the arm 51 is rotated to the position betweenthe openings 101 b and 101 c, the sample scooping member 52 is broughtinto the stand-by state at that position in order to transfer the nextetched sample to the sample table 22.

[0109] After receiving the post-processed sample 170, the sampledelivery member 130 a of the sample table 130 is moved down.Accordingly, the post-processed sample 170 is delivered from the sampledelivery member 130 a of the sample table 130 to the sample table 130and placed on its sample disposition surface (FIG. 4C). The sample table130 having the post-processed sample 170 is moved up so that the opening101 d is closed air-tight by the sample table 130 (FIG. 4D). The covermember 131 is moved up under this state. The rise of the cover member131 is stopped when it reaches the position (FIG. 4E) at which the riseof the sample delivery member 130 a of the sample table 130 is notprevented, and, moreover, the sample scooping member 62 of the arm 61 isnot prevented from reaching the position where it can receive thepost-processed sample 170 from the sample delivery member 130 a of thesample table 130. Under this state, the sample delivery member 130 a ofthe sample table 130 is first moved up. Accordingly, the post-processedsample 170 is delivered from the sample table 130 to its sample deliverymember 130 a (FIG. 4F).

[0110] Next, when the arm 61 is rotated in the direction of the sampletable 130, the sample scooping member 62 is rotated in the direction ofthe sample table 130. This rotation of the sample scooping member 62 isstopped when it reaches the position where the post-processed sample 170can be exchanged between it and the sample delivery member 130 a of thesample table 130, or, in other words, the position which corresponds tothe back of the post-processed sample 170 held by the sample deliverymember 130 a of the sample table 130 (FIG. 4G). The sample deliverymember 130 a of the sample table 130 is then moved down so that thepost-processed sample 170 is delivered from the sample delivery member130 a of the sample table 130 to the sample scooping member 62. Afterreceiving the post-processed sample 170, the sample scooping member 62is rotated towards the sample table 32 inside the wet-processing chamber31 when the arm 61 is rotated in the direction of the wet-processingchamber 31.

[0111] After delivering the post-processed sample 170 to the samplescooping member 62, the sample delivery member 130 a of the sample table130 is further moved down to the position which is below the sampledisposition surface of the sample table 130. The cover member 131 isthereafter moved down and the opening 101 d is closed air-tight by thecover member 131. The sample table 130 is again moved down under thisstate and the next post-processed sample is delivered to and placed onthis sample table 130.

[0112] The rotation of the sample scooping member 62 having thepost-processed sample 170 is stopped when it reaches the position atwhich it can exchange the post-processed sample 170 between it and thesample delivery member of the sample table 32. The sample deliverymember of the sample table 32 is moved up under this state. Accordingly,the post-processed sample 170 is delivered from the sample scoopingmember 62 to the sample delivery member of the sample table 32. Afterdelivering the post-processed sample 170, the sample scooping member 62is moved outside the wet-processing chamber 31 in order to prepare foracceptance of the next post-processed sample. The opening 34 is thenclosed.

[0113] The sample delivery member of the sample table 32 is moved downafter receiving the post-processed sample 170. Accordingly, thepost-processed sample 170 is delivered from the sample delivery memberof the sample table 32 to the sample table 32 and is placed on itssample disposition surface. The processing solution is then supplied ata predetermined flow rate from the processing solution feed apparatus tothe processed surface of the post-processed sample 170 placed on thesample table 32 through the processing solution feed pipe. At the sametime, the post-processed sample 170 is rotated by the operation of themotor. In this manner, wet-processing of the post-processed sample 170is executed.

[0114] Nitrogen gas, for example, is introduced into the wet-processingchamber 31 by the inert gas introduction means so that wet-processing iscarried out in a nitrogen gas atmosphere. The waste liquor generated bythis wet-processing is discharged outside the wet-processing chamber 31through the waste liquor discharge pipe.

[0115] After such a wet-processing is complete, the supply of theprocessing solution, the rotation of the sample 170, and the like, arestopped, and the sample delivery member of the sample table 32 is movedup. During this rise, the wet-processed sample 170 is delivered from thesample table 32 to its sample delivery member. The rise of the sampledelivery member receiving the wet-processed sample 170 is stopped at theposition where this sample 170 can be exchanged between the sampledelivery member and the sample scooping member 72. The sample scoopingmember 72 is moved under this state towards the sample table 32. Thismovement is stopped when the sample scooping member 72 reaches theposition where the wet-processed sample 170 can be exchanged between thesample scooping member 72 and the sample delivery member of the sampletable 32. The sample delivery member of the sample table 32 is thenmoved down. Accordingly, the wet-processed sample 170 is delivered tothe sample scooping member 72. After the wet-processed sample 170 isremoved, the sample delivery member of the sample table 32 prepares forthe acceptance of the next post-processed sample.

[0116] The sample scooping member 72 having the wet-processed sample 170is further moved to the dry-processing chamber 41 from thewet-processing chamber 31, passing through the opening towards thesample table 42 through the arm 71. This movement is stopped when thesample scooping member 72 reaches the position at which thewet-processed sample 170 can be exchanged between the sample scoopingmember 72 and the sample delivery member of the sample table 42. Thesample delivery member of the sample table 42 is then moved up.Accordingly, the wet-processed sample 170 is delivered to the sampledelivery member of the sample table 42. After the wet-processed sample170 is removed, the sample scooping member 72 is once moved back and thesample delivery member of the sample table 42 is moved down.Accordingly, the wet-processed sample 170 is delivered from the sampledelivery member of the sample table 42 to the sample table 42 and isplaced on its sample disposition surface.

[0117] The sample table 42 is heated externally by supply of power tothe heater 43 and the wet-processed sample 170 is heated through thesample table 42. The temperature of the wet-processed sample 170 iscontrolled to a predetermined temperature by adjusting the feed quantityto the heater 43. Thus the wet-processed sample 170 is dry-processed.Nitrogen gas, for example, is introduced into the dry-processing chamber41 by the inert gas introduction means and dry-processing is carried outin the nitrogen gas atmosphere.

[0118] After dry-processing is thus complete, the sample delivery memberof the sample table 42 is moved up. During this rise, the dry-processedsample 170 is delivered from the sample table 42 to its sample deliverymember. The rise of the sample delivery member of the sample table 42receiving the dry-processed sample 170 is stopped when the dry-processedsample 170 can be exchanged between it and the sample scooping member72. Under this state, the sample scooping member 72 is again movedtowards the sample table 42 through the arm 71. This movement is stoppedwhen the sample scooping member 72 reaches the position at which thedry-processed sample 170 can be delivered between the sample scoopingmember 72 and the sample delivery member of the sample table 42. Thesample delivery member of the sample table 42 is then moved down.Accordingly, the dry-processed sample is transferred to the samplescooping member 72. The sample delivery member of the sample table 42from which the dry-processed sample 170 is removed prepares foracceptance of the next wet-processed sample.

[0119] The sample scooping member 72 having the dry-processed sample 170is further moved from the dry-processing chamber 41 to the samplerecovery chamber 150 through the opening towards the cassette table 151through the arm 71. This movement is stopped when the sample scoopingmember 72 reaches the position where the dry-processed sample 170 can bedelivered between it and the cassette 161 placed on the cassette table151.

[0120] The cassette 161 has a plurality of storage grooves in thedirection of height, for example, and is positioned so that theuppermost groove can accept and store the sample. The cassette 161 isintermittently moved down by a predetermined distance under this stage.Accordingly, the dry-processed sample is supported by the uppermostgroove of the cassette 161 and is recovered and stored therein.

[0121] Nitrogen gas, for example, is introduced into the sample recoverychamber 150 by the inert gas introduction means so that thedry-processed sample 170 is stored in a nitrogen gas atmosphere and isonce preserved in the sample recovery chamber 150. Recovery of thedry-processed samples into the cassette 161 is sequentially conducted;and after this recovery is complete, the cassette 161 is dischargedoutside the sample 10 recovery chamber 150. The sample thus taken outfrom the sample recovery chamber 150 while stored in the cassette 161 istransferred to the next step.

EXAMPLE

[0122] The following sample is prepared several times. First, a 3,000Å-thick silicon dioxide film 172 is formed on a Si substrate 171 such asshown in FIG. 6, a laminate wiring of a TiW layer 173 and an Al—Cu—Sifilm 174 is formed on the former and a photoresist 175 is used as amask. This sample is processed by use of the apparatus shown-in FIGS. 2,3, 4A-4G and 5A and 5B.

[0123] The etching conditions are BCl₃+Cl₂ as the processing gas, with aflow rate of the processing gas of 150 sccm (standard cm³ per minute), aprocessing pressure of 16 mtorr, a microwave output of 600 W and a radiofrequency bias of 60 W.

[0124] The samples which are passed through all the subsequent stepswithout any processing after etching are referred to as (A), those whichare etched, plasma post-processed but are not passed through the wet-and dry-processings are referred to as (B), those which are subjected tothe predetermined processings at all the steps are referred to as (D)and those which are not plasma post-processed after etching but are wet-and dry-processed are referred to as (C). The corrosion-proofing effectsof these samples are then compared.

[0125] The processing conditions in the plasma post-processing chamberare O₂+CF₄ as the processing gas, with a flow rate of the processing gasof 400 sccm (O₂) and 35 sccm (CF₄) and a processing pressure of 1.5Torr, and the plasma is generated by use of a 2.45 GHz microwave. Inthis case, the plasma post-processing is mainly intended to ash (remove)the photoresist and to remove chlorides remaining on the protective filmon the pattern sidewall and the pattern bottom portion, and ashing isconducted for about 30 seconds and additional processing under the samecondition is conducted for about one minute. In wet-processing, spinningwater wash treatment with pure water is conducted for one minute andspinning drying is conducted for 30 seconds. Furthermore, the sampletable is heated to 150° C. in the nitrogen gas atmosphere and thewet-processed sample is left standing for the minute for dry-processing.

[0126] When those samples (B) which are etched and then plasmapost-processed but are not passed through the wet-processing, that is,water washing treatment and dry-processing, are observed through anoptical microscope, spot-like matters analogous to corrosion can beobserved within about one hour. Accordingly, they are observed infurther detail by SEM. Fan-like corrosion products 180 starting from theboundary between the TiW layer and the Al—Cu—Si layer are observed asshown in FIG. 7. Even though the mixing ratio of CF₄ with respect to O₂is changed to from 5 to 20%, the processing pressure is changed to from0.6 to 2 Torr and the sample temperature is raised to 250 C., corrosionanalogous to that described above is observed within a few hours in eachcase.

[0127] It is therefore believed that particularly in a laminate layerwiring, or alloy wiring, containing different kinds of metals havingmutually different ionization potentials, corrosion is generated andaccelerated by so-called electrolytic corrosion due to batteryoperation.

[0128] To sufficiently prevent the occurrence of such corrosion, it hasbeen found that plasma post-processing alone after etching is notsufficient and even limited amounts of chlorine components must beremoved completely.

[0129] As described above, therefore, processing was carried out undervarious conditions to examine the time till the occurrence of corrosionafter processing. The result is shown in FIG. 8.

[0130] As can be seen from FIG. 8, in the case of wiring materials suchas the laminate layer wiring in which corrosion is vigorous, the plasmapost-processing such as resist ashing after etching, or water washingprocessing and drying processing after etching without carrying outplasma post-processing, cannot provide a sufficient corrosion-proofingeffect. A high corrosion-proofing effect for more than 30 hours can onlybe obtained by carrying out in series the etch-processing, the plasmapost-processing such as ashing of the resist, the water washingprocessing and the dry-processing.

[0131] Besides the washing process described above, the same effect ofinhibition of corrosion can be obtained by passivation processing with amixture of nitric acid and hydrogen fluoride or nitric acid, which alsoserves to remove any residues after plasma etching, before the waterwashing processing.

[0132] In order to remove the reactive products on the pattern sidewallthat cannot be removed sufficiently by the plasma post-processing, it isadvisable to conduct liquid processing by use of a weakly alkalinesolution or a weakly acidic solution (e.g. acetic acid) after plasmapost-processing subsequent to etching and then to carry out the waterwashing processing and dry-processing. In this manner, the chlorinecomponents can be remove more completely and the corrosion-proofingeffect can be further improved.

[0133] In the embodiment described above, the time till completion ofthe wet-processing of the plasma post-processed sample is limited toabout one hour because corrosion occurs within about one hour as shownin FIG. 8 in the case of the sample shown in FIG. 6. However,wet-processing is preferably completed as quickly as possible. In otherwords, the plasma post-processed sample is preferably transferredimmediately after completion of plasma post-processing from the plasmapost-processing apparatus to the wet-processing apparatus. Though theplasma post-processed sample is transferred inside the atmosphere in theembodiment described above, it may be transferred in a vacuum or in aninert gas atmosphere. Transfer in such an atmosphere is extremelyeffective when the time from plasma post-processing till the start ofwet-processing is longer than the corrosion occurrence time in theatmosphere, for example. In such a case, means may be disposed betweenthe plasma post-processing apparatus and wet-processing apparatus forpreserving the plasma post-processed sample in a vacuum or in the inertgas atmosphere.

[0134]FIG. 9 explains a second embodiment. The difference of thisembodiment from the first embodiment shown in FIG. 1 lies in that apassivation-processing apparatus 190 is additionally disposed on thedownstream side of the dry-processing apparatus 40. In this case, thesample transfer means 90 has the function of transferring thedry-processed sample from the dry-processing chamber (not shown) of thedry-processing apparatus to a passivation-processing chamber (not shown)of the passivation-processing apparatus 190. Additionally, sampletransfer means 200 for transferring the passivated sample to a recoverycassette (not shown), for example, is disposed. Like reference numeralsare used to identify like constituents as in FIG. 1 and theirexplanation will be omitted.

[0135] In FIG. 9, the etched, plasma post-processed sample (not shown)is transferred into the wet-processing chamber (not shown) of thewet-processing apparatus 30 by the sample transfer means 60 and isplaced on the sample disposition surface of the sample table (not shown)as the wet-processing station inside the wet-processing chamber. Theplasma post-processed sample placed on the sample table in thewet-processing chamber is subjected to development solution processing.Residues, and the reactive products on the pattern sidewall, afteretching are completely removed by such wet-processing. If the samplecontains Al as its component, Al, too, is partly dissolved. When such asample is dry-processed and taken out into the atmosphere, for example,oxidation as a form of corrosion will occur disadvantageously.Therefore, the sample subjected to development and dry-processing in thedry-processing chamber of the dry-processing apparatus 40 is transferredinto the passivation-processing)chamber of the passivation-processingapparatus 190 and is placed on a sample disposition surface of thesample table (not shown) at the processing station in thepassivation-processing apparatus 190. Gas plasma forpassivation-processing, or oxygen gas plasma in this case, is generatedin or introduced into the passivation-processing chamber. Ozone may beused instead of oxygen. The dry-processed sample placed on the sampletable in the passivation-processing chamber is passivation-processed bythe oxygen gas plasma. The passivation-processed sample is transferredfrom the passivation-processing chamber to the recovery cassette by thesample transfer means and recovered and stored therein.

[0136] Passivation-processing may use nitric acid, besides the chemicalsdescribed above.

[0137] Since the present invention can sufficiently remove the corrosivematerials generated by etching of the sample, it provides the effectthat corrosion of the sample after etching can be prevented sufficientlyirrespective of the type of sample.

[0138] As described previously, according to the present invention thewet-processing apparatus 30 (see FIG. 1) has plural sample tables, andeach of them can carry out parallel processing or series processing(wet-processing) of the samples. A supply means for chemical liquid usedfor the wet-processing has introduction nozzles, which are classifiedfor acid, alkali and pure water processing liquids, and each chemicalliquid is controlled to have a temperature from, e.g., room temperatureto 100° C. The processing waste liquid is changed by the acidprocessing, the alkaline processing and the water processing. Since alloperations in this system are controllable by a controller comprising apersonal computer provided in this system, the processing sequence, inother words, the flow rate, the flow rate of the chemical liquid, therotation amount of the spinner and parallel or series processing, etc.can be programmed freely.

[0139] Reference is made to FIGS. 10 and 11, showing this aspect of thepresent invention having a plurality of wet-processing means (e.g.,two-wet processing stations respectively having sample tables 32 a and32 b ). Reference characters in FIGS. 10 and 11, which are the same asin previously discussed drawing figures in the present application(e.g., FIGS. 2 and 3), represent structure having effectively the samefunction as previously discussed, and will not be further describedexcept with respect to any differences with the previously discussedstructure. Each of sample tables 32 a and 32 b has a sample installationsurface on the respective surface. Each of the sample tables 32 a and 32b is provided extending in a substantially horizontal direction, on anupper end of a respective support shaft 33, the respective sampleinstallation surface forming the upper surface of the sample table. Thesample installation surface of,the respective sample tables 32 a and 32b is positioned at a lower portion than the sample scooping member 62 ofthe arm 61. Each of the sample tables 32 a and 32 b provides a samplereceiving member (not shown in FIGS. 10 and 11), respectively. Note thatin FIG. 10, the wet processing room 31 contains the two (2) sampletables 32 a and 32 b. After treatment on the sample table 130 of theplasma post-processing apparatus, the sample is transferred, e.g., bysample scooping member 62 of the arm 61, to support member 173, bytransfer techniques as discussed previously. From support member 173,transfer arm 172 can be used to transfer the sample to sample table 32 aor to 32 b, depending on availability for the wet processing and whetherseries or parallel processing is to be carried out.

[0140] If series processing is to be performed, the sample istransferred first, e.g., to sample table 32 a from support member 173,and thereafter is transferred (after wet-processing on sample table 32a) to sample table 32 b for wet-processing on sample table 32 b.Thereafter, the sample is transferred to sample table 42 of thedry-processing chamber 41, for processing therein as discussedpreviously. Of course, treatment with different liquids can be performedat each of sample table 32 a and sample table 32 b, respectively.

[0141] If parallel processing is to be performed, a sample can(alternatively) be transferred from support member 173 to either sampletable 32 a or sample table 32 b by transfer arm 172, depending, e.g., onavailability of the sample table. After, e.g., treatment with aplurality of different treatment liquids at the respective sample table32 a or 32 b, the sample can be transferred by transfer arm 172 tosample table 42 of e the dry-processing chamber 41.

[0142] Next will be described a parallel wet-processing particularlyuseful where the wet-processing takes a longer amount of time than,e.g., a time period required for treatment in buffer chamber 100. Thisparallel wet-processing will be discussed in connection with FIG. 15.Parallel wet-processing is particularly effective to improve the throughoutput when the period required for the wet-processing is much longerthan the period required for other (prior) processes, such as processesin the buffer chamber 100. In order to simplify the explanation ofparallel wet-processing, it is assumed that the periods for etchingprocess on the table 15 and ashing process on the table 22 are 120seconds, that the period for wet-processing on the table 32 a or 32 b is240 seconds, and that any periods for transfer of the sample from onelocation to another location are neglected. Samples A, B, C . . . aresequentially etched on the table 15 every 120 seconds and transferred totable 22 to be ashed there every 120 seconds, as shown in FIGS. 15(a)and 15(b). Etched and ashed sample A is transferred to the table 32 aand rinsed there for 240 seconds. Though ashing for sample B is ended atthe half-time point of the period during which sample A is rinsed, theashed sample B would have to wait to be wet-processed on the table 32 atill the wet-processing for Sample A on the table 32 a is finished.However, another table 32 b is available to wet-process sample B,without the waiting time, since wet-processing for a previous sample onthe table 32 b has finished by the end of the period for ashing sampleB, that is, the half time point of the period for wet-processing sampleA. Samples A, B, C, . . . are alternately transferred to tables 32 a and32 b with a half time shift of the wet-processing period as shown inFIGS. 15(c) and 15(d).

[0143] The wet-processing for each sample requires 240 seconds which istwice 120 seconds required for the etching or ashing process. Since therough output of the over-all system is determined by the longest periodin the sequential processing, the through output of the system with onewet-processing table is determined by 240 seconds. However, withparallel wet-processing, wet-processing for each sample can be finishedevery 120 seconds. Since the longest period which determines the throughoutput of the system is shortened by half, the through output isimproved.

[0144] As seen in the foregoing, sample waiting time, for thewet-processing, can be reduced. Accordingly, through use of thepresently disclosed parallel treating the total time, from beginning toend, of processing a sample can be reduced.

[0145] Next, a sample processing method using the above sampleprocessing apparatus will be explained. As the sample 170, a 3000Å-thick silicon dioxide film 172 is formed on a silicon substrate asshown in FIG. 6; on the former a laminated wiring of a TiW layer 173 andan Al—Cu—Si film 174 are formed, and the sample 170 uses a photoresist175 as a mask.

[0146] As the etching processing conditions, the selected conditions areBCl₃ +C1 ₂ as the etching processing gas, a flow rate of the processinggas of 150 sccm, a processing pressure of 16 mTorr, a microwave outputof 600 W and RF bias of 60 W.

[0147] The samples which are passed through all the subsequent stepswithout any processing after the etching processing are referred to as(A), those which are plasma post-processed after the etching processingbut are not passed through the wet-processing and the dry-processing arereferred to as (B), those which are subjected to the predeterminedprocessings at all the steps are referred to as (D), and those which arenot plasma post-processed after the etching processing but arewet-processed and dry-processed are referred to as (C). Thecorrosion-proofing effects of these samples are then compared.

[0148] Besides, the processing conditions in the plasma post-processingchamber are O₂+CF₄ as the processing gas, a flow rate of the processinggas of 400 sccm (O₂) and 35 sccm (CF₄) and a processing pressure of 1.5Torr, and the plasma is generated by use of a 2.45 GHz microwave.

[0149] In this case, the plasma post-processing is mainly directed toashing the photoresist and to remove chlorides remaining on theprotective film on the pattern side wall and the pattern bottom portion,and the ashing processing is conducted for about 30 seconds and theadditional processing under the same plasma condition is conducted forabout one minute.

[0150] Further, in the wet-processing, a spinning water wash treatmentwith pure water is conducted for one minute and the spinning drying isconducted for 30 seconds. Furthermore, the sample table is heated to150° C. by the heater under the nitrogen gas atmosphere and thewet-processing sample is left standing on it for one minute for thedry-processing.

[0151] As a result, when those samples which are etching-processed andthen plasma post-processed but are not passed through thewet-processing, that is, the water washing treatment and thedry-processing, are observed through an optical microscope, spot-likematters analogous to the corrosion can be observed within about onehour.

[0152] Accordingly, they are observed in further detail by SEM. As aresult, fan-like corrosion products 180 starting from the boundarybetween the TiW layer and Al—Cu—Si layer are observed, as shown in FIG.7.

[0153] Therefore, even though the mixing ratio of CF₄ with respect to O₂is changed from 5-20%, the processing pressure is changed from 0.6-2Torr and the sample temperature is raised to 250° C., corrosionanalogous to the one described above is observed within a few hoursafter the processings in either case.

[0154] The corrosion such as described above cannot be observed in anAl—Cu—Si single layer wiring film. It is therefore believed that in thelaminated layer wiring of different kinds of metals having mutuallydifferent ionization tendencies, the corrosion is generated andaccelerated by so-called electrolytic corrosion due to a batteryoperation.

[0155] To sufficiently prevent the occurrence of such corrosion, it hasbeen found that the plasma post-processing alone after the etchingprocessing is not sufficient and even limited amounts of the chlorinecomponents must be removed completely.

[0156] As described above, therefore, the processings were carried outunder various conditions to examine the time till the occurrence of thecorrosion after the processing, and the result shown in FIG. 8 wasobtained.

[0157] As can be seen from FIG. 8, in the case of the wiring materialssuch as the laminated layer wiring in which corrosion is vigorous, theplasma post-processing such as a resist ashing after the etchingprocessing, or the water washing processing and the drying processingafter the etching processing without carrying out the plasmapost-processing, cannot provide a sufficient corrosion-proofing effect.

[0158] A high corrosion-proofing effect for more than 30 hours can firstbe obtained by carrying out in series the etching processing, the plasmapost-processing such as the ashing of resist, the water washingprocessing and the dry-processing.

[0159] Further, besides the processing described above, a same effectcan be obtained by processing with a mixture of nitric acid andhydrofluoric acid, which also serves to remove any residues after theetching, before the water washing processing.

[0160] In order to remove the protective film on the pattern side wallthat cannot be removed sufficiently by the plasma post-processing, it isadvisable to process the sample by wet-processing using a weaklyalkaline solution or a weakly acidic solution (for example, aceticacid), after the plasma post-processing subsequent to etching, and thento carry out the water washing processing and the dry-processing. Inthis manner, the chlorine components can be removed more completely andthe corrosion-proofing effect can be further improved.

[0161] In FIG. 12, a relative relation between the acetic acidconcentration, and the corrosion occurrence percentage, whenwet-processing is conducted using acetic acid, is shown. As can be seenfrom FIG. 12, when the acetic acid concentration is 10-20%, thecorrosion occurrence percentage is a minimum value.

[0162] Further, in FIG. 13, a relation between processing time and theresidue chlorine amounts on the sample surface is shown. As can be seenfrom FIG. 13, the residue chlorine amount lowers gradually up to 4minutes from the start of the processing, after which it becomesconstant. Accordingly, it can be seen that desirably the processing time(for wet-processing) is more than four minutes.

[0163] However, since the total time for both etching processing andashing processing is one to two minutes, and since four minutes are longremarkably, waiting time for the wet-processing is long where only asingle wet-processing station is used. According to the presentinvention, having a plurality of wet-processing stations andparticularly where parallel processing is performed, the through-put isaccelerated in this wet-processing so that lowering of the through-putcan be avoided.

[0164] Moreover, according to the present invention chemical liquidprocessing and the water washing processing can be conducted in seriesand successively.

[0165] Further, in the case where acetic acid alone is used for chemicalwet-processing, during the sample processing the adsorbed chlorine onthe sample surface is dissolved in water; a high concentrationhydrochloric acid is generated locally and Al is locally etched.Accordingly, in order to not locally etch Al, a buffer liquid comprisinga weak acid (for example, acetic acid) and a weak alkali (for example,ammonia) can be used.

[0166] The buffer action of the acetic acid-ammonia buffer liquid isshown in FIG. 14. Corrosion-proofing effect is seen at every bufferconcentration. However, in the alkali region Al is etched; accordingly,it is desirable to use the buffer liquid in the acid region.

[0167] Further, by increasing the wet-processing temperature, thenecessary processing time shown in FIG. 13 can be shortened. At 40° C.the wet-processing requires five minutes; by making the temperature ofthe processing liquid 80° C. the wet-processing can be obtainedeffectively in about two minutes. The temperature of the processingliquid can be controlled from room temperature to 100° C., as discussedpreviously. Accordingly, relatively high temperature liquidwet-processing treatments can be advantageous.

[0168] While we have shown and described several embodiments inaccordance with the present invention, it is understood that the same isnot limited thereto, but is susceptible to numerous changes andmodification as known to one having ordinary skill in the art, and wetherefore do not wish to be limited to the details shown and describedherein, but intend to cover all such modifications as are encompassed bythe scope of the appended claims.

What is claimed is:
 1. An apparatus for processing a sample that hasbeen etched in a first plasma chamber, the etching being performed topattern the sample through a resist wherein the etching leaves residualcorrosive compounds on the etched sample, comprising: a second plasmachamber, connected to said first plasma chamber, adapted to have asecond plasma containing oxygen generated therein for application to theetched sample, said second plasma being formed in a gas atmospherecomprising at least oxygen, to remove said resist and said residualcorrosive compounds from the sample, leaving remaining corrosivecompounds; and a rinsing section, connected to said second plasmachamber, and adapted to apply to the sample from said second plasmachamber, a liquid, to remove said remaining corrosive compounds, formedin said first plasma chamber but not completely removed by said secondplasma in said second plasma chamber.